ktgumbo

Hey guys, I do not know that much about engine stuff, so here is my question. With sky rocket gas prices here in the bay area( $3.29 a gallon for super unleaded 91 Octane) can the "Black box or ECU" not sure what it is called tell if we use regular 87 gas instead of 91? I was just curious if I did use normal unleaded and I had some kind of engine issue, if Acura can tell from this that
I had ever used normal unleaded. Thx

Sonic One

uhm...I'd suggest you just use 91. If you can spend money on your car, you should be avoid putting in less than 91. It has harmful effects on your engine and may start pinging.

legend4life

Actually it's probably pretty safe for you to even run regular 87 octane in your car. There are no harmful effects, it just has less octane boosting additives in it. I'm sure your car has knock sensors and will automatically retard the timing for knock when running lower octane. My car requires premium and I'm running regular with no problems for the same reason. And even if Acura knows you run 87 octane they are not going to treat you or your car/service any different becuase of that. But to answer your question, no they should not be able to tell what octane you run from your ecu.

fuzzy02CLS

iTrader: (2)

No black box. 87 will not harm the engine/car. You will get worse milage, & the car will not run at it's peak. But the cars computer will compensate for the lower octane gas.

resedaruss

iTrader: (1)

I have had gas stations fill me with unleaded after I asked for premium. Afterwards, I didn't notice any ill effects beyond the slight detuning necessary to eliminate pinging. (The computer monitors pinging and detunes automatically if warranted.)

The owner's manual points out that unleaded can be used if necessary but that optimum performance won't be achieved. I personally haven't noticed much difference on those rare occasions when I got lower octane gas because of pumper-error. The difference is subtle in my opinion.

Another reason to stick to premium gas is that some refiners (the old Mobil for one--before the merger to Exxon-Mobil) put a better detergent package in their premium gases. Mobil Research engineers showed me that. A better detergent package makes for cleaner burning. I've used premium ever since I found that out.

mrsteve

iTrader: (1)

If I was in Jersey and someone filled up my CL-S with 87 octane I'd make them drain it out and re-fill it.

fuzzy02CLS

iTrader: (2)

My co worker has a TLS & has used 87 for the while time he's owned it. He doesn't notice a difference, but he also doesn't drive it much & is not a car guy.

mclarenf3387

All the gas on the East Coast comes from the same refinery located in NJ.
The only difference in gasses is addetives, which probably only make a marginable difference in performance.

You need to run 93 though, thats different. Otherwise you go

Lord Helmet

Personally, even though gas prices are thru the roof, it's only going to cost you $2-$3 more per tankfull when using premium. I paid alot of money for my car and I want it to last me for years to come. In no way would I sacrifice my engine's quality or performance for a few bucks per tankfull. Use premium, I think it's worth it. Just my $.02

Lord Helmet

BTW, here in CO, 91 is the highest rating you can buy. Something to do with the altitude.

mclarenf3387

Want a cookie?

Lord Helmet

resedaruss

iTrader: (1)

I'm not sure where this rumor comes from, but there are 3 refineries in Southern New Jersey within 25 miles of my house. Who knows how many there are in all of New Jersey--or on the entire east coast. If only one refinery in NJ were providing gas to the entire East Coast, one would have to wonder where the gas from all the other NJ refineries--and all the rest of the east coast refineries is being sent. In actuality, no one refinery, in NJ or anywhere, has a lock on everyone on the east coast.

Secondly, it is valid to wonder if detergent packages make a difference. This is a preference thing.

Those that feel detergent packages are a sales gimmick can get their gas from dealers that take delivery of spec-gas without detergent packages (24-hour mini marts, etc.). I don't know of any major-brand gas stations that don't use a detergent package--although it is possible there are some. The reduction in cost of spec-gas is partly a result of savings incurred from not having to put a detergent package in the gas and also partly because they don't have a large organization to support (like name-brand retailers have).

Detergent packages won't change performance on any single tank except as it relates to carbon buildup, etc. over time. But after all is said and done, cleaner engines perform better. Detergent packages do make the fuel burn cleaner and prevent buildups that reduce performance over time. Believers opine, for example, that spark plugs will look cleaner and produce a better spark when gas with a good detergent package has been used consistently. Believers fill up at name brand stations that tend to have the best detergent packages. Also, premium name-brand gas tends to have better detergent packages than lower-octane name-brand gas (that was true of Mobil when I used to work for them--before they became Exxon-Mobil).

dabusabus1

lol

AuCLSman

high compression engines are designed to function with fuel of specific minimum octane rating. you own such an auto. the engine will still function albeit less efficiently.
therefore more volumn of 87 octane fuel will be required per combustion cycle to achieve the same power output than say, 92 octane fuel. less output means lower gas mileage at the same relative speed..
additionally, as noted in posts #4/#5, the ECM reads pre-detionation when lower octane fuel is used and adjusts timing to compensate.
pre-detionation is BAD for a high compression engine , continued consistant use will cause internal component damage due to pre-detionation.
(excellant discussion on fuel additive, combustion charactoristics of gasolines can be found in this forum, using the search tool.) if, you are interested in the knowledge.
the octane additives i speak of are not the same additives spoken of in post #13, which are valid also.
two separate issues/answers addressing your original query

GreenMonster

If you're worried about $100-200 dollars a year in total savings, you shouldn't be driving a acura.

It's actually about $114 a year for me.... Lets do the math...

Car gets 21mpg... I drive 12,000 miles a year (both figures are rough estimates). 12K/21 = 571 gallons of gas...

If the cheapest gas is 20cents cheaper then premium then 571x.20=$114.28

I'm not about to worry about $114.28 a year.... If I were, I'd be driving a civic

edit: And I'm a notorious cheap bastard.

Sonic One

What he said.

NiteQwill

Exactly... these damn threads come up every 2 weeks...

If you cannot afford to put the RIGHT gas into the car... well, you shouldn't be driving it.

drock03

I agree....not much of a $ difference at all........Even if you drove 24,000 miles a year....that's still pretty damn cheap....$228

HohLake

And this doesn't factor in that you won't be getting 21 mpg on 87 octane.

I notice a mpg differrence between 93 and 92, can't imagine what 87 will do to mileage.

kaih

93 Octane gas does not have more energy than 87 octane gas. Cars that don't require high octane gas do not make more horsepower using premium. Only cars that were designed to take premium take advantage of the extra timing to produce additional horsepower.

The knock sensor retards timing when it senses detonation which generally occurs under heavy loads or WOT. So at regular driving and cruising speeds why would you expect to see a drop in MPG. The power output should be the same as long as you keep your foot out it, which I doubt anybody here does.

mclarenf3387

You're right, I was wrong. I was thinking of the NJ oil Reserve which supplies most of the East coast/Nort East. Although after looking it up, even then there are 2 smaller ones in CT and RI, bastards at the reserve lied to me

Meh, as for detergent packages, I doubt it makes a huge difference. Look at all the people with Civics that go for 300k miles. Doubt all of them are using name brand gas most of the time.

Anyways, thats a differnt argument.

HohLake

You might be right, but all I know is my own experience. When I first bought the car I was using a no name premium that was 92 octane and was seeing 18-19 mpg, 100% city driving. When I switched to Shell 93 octane I noticed an immediate increase to around 20 mpg.

I suppose it could of been something else that increased my mileage(detergents, weather, not being such a lead foot), but at the time it seemed to be an immedialte change to the higher mpg. That was 2 years ago that I switched, and I still continue to get around 20, unless I'm in a mood, then of course the miles go down.

ktgumbo

Well i have used unleaded now for the last 2 tanks. I have averaged about 1-2 mpg increase than before. I have decided to go back to using 91 since the price difference is minimal.